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Thread: subcooling

  1. #1
    Join Date
    Jul 2005
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    8
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    goodman, 2 ton, high efficiency, mid 90s, 15 foot lineset, bullet type metering device into cap tubes not txv.

    liquid line 167 psig on gauges 90 r 22
    liquid line temp 80
    suction line 69 psig
    ambient 73 degrees
    I'm not one hundred percent on what subcooling should be. I forgot the tp chart.

  2. #2
    Join Date
    Jun 2005
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    You should be charging by superheat

  3. #3
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
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    11,847
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    From the info you've given you're running a 10 degree subcooling. That's about normal.

    However, as prodiyer said, check and charge a piston (bullet) metering system with superheat. Difference between saturated vapor temperature in evap and temperature of suction line outside condenser is called "compressor superheat". It lets you know how well the compressor is being cooled and if your evap is running flooded, proper, or starved.

    Piston metered systems are critical charge. If you don't nail it, the system will suffer performance loss.
    Psychrometrics: the very foundation of HVAC. A comfort troubleshooter's best friend.

  4. #4
    Join Date
    Jul 2005
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    Thread Starter
    what should the superheat be. 12 is the number that comes to mind

  5. #5
    Join Date
    Apr 2003
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    Post all the needed data for a competent answer to your question.

    Model number __

    SP __ /T __ LP __ /T __
    ST __ LT __
    SH __ SC __
    AT __ CT __
    IWB __ IDB __
    Evap ST __

  6. #6
    Join Date
    Jul 2005
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    Thread Starter
    superheat was 65 minus 39. 26 on a 70 degree day

  7. #7
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    Jul 2005
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    Thread Starter
    do you want me to make you a mollier diagram for you julz?

  8. #8
    Join Date
    Jul 2005
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    Thread Starter
    mod number is cj24 1ab

  9. #9
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    Jul 2005
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    Thread Starter
    THanks to anyone who replies

  10. #10
    Join Date
    Jun 2005
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    your gonna need atleast the indoor wet bulb and outdoor temp to determine what your superheat should be.

  11. #11
    Join Date
    Jul 2005
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    Thread Starter
    thats not gonna happen today so i'll just get to it later. thanks

  12. #12
    Join Date
    Apr 2003
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    Originally posted by metaleraus
    do you want me to make you a mollier diagram for you julz?
    If people want correct answers... we need information to do so!
    If, you are not willing to get/or ask what some of the info needed is... why should we spend our time trying to help?

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